Stomach mostly visible with shortened attractive garment (5)
I believe the answer is:
tunic
'shortened attractive garment' is the definition.
'tunic' can be an answer for 'garment' (historical type of garment). I am not certain of the 'shortened attractive' bit.
'stomach mostly visible' is the wordplay.
'stomach' becomes 'tum' (synonyms).
'mostly' means to remove the last letter (most but not all of the word).
'visible' becomes 'nic' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'tum' with its last letter taken off is 'tu'.
'tu'+'nic'='TUNIC'
'with' is the link.
Can you help me to learn more?
(Other definitions for tunic that I've seen before include "Knee-length cloak" , "School garment" , "Cut in (anag)" , "Belted coat" , "Military uniform" .)